Ultrasound biomocroscopy (UBM) allows high-resolution imaging of the anterior segment due to ultrasound transducers between 50 and 100 MHz. At present stage of experience, mainly analysis of iris and ciliary body structures seem to be clinically rewarding. This is demonstrated by two similar looking tumors, involving the chamber angle. By means of UBM it was possible to differentiate between cystic and solid growths and to assess tumor extensions.